High-frequency characterization of sub-0.25-μm fully depleted silicon-on-insulator MOSFETs

A cutoff frequency, f
_T
, of 85 GHz was measured on a fully-depleted silicon-on-insulator (FDSOI) n-MOSFET with a gate length of 0.15 μm. The p-MOSFET with 0.22-μm gate length has an f
_T
of 42 GHz. The high-frequency equivalent circuits were derived from scattering parameters for MOSFETs with various gate lengths. The effects of gate length and other device parameters on the performance of FDSOI MOSFETs at RF are discussed.